Detection method for monitoring open-short circuit functional defects of printed-circuit board step hole

Abstract

The invention discloses a detection method for monitoring open-short circuit functional defects of a printed-circuit board step hole. The method comprises the following steps that firstly, according to the depth of a step, a flying-probe testing machine with different needle lifting heights is selected, and a test file is made according to the parameter requirement of the flying-probe testing machine; secondly, a needle type needle head is selected to be fixed to the tail end of a needle bed, and a step testing needle of an integrated structure is made by injection molding of the needle type needle head and the elastic needle bed; thirdly, needle tip correction is conducted on the changed step testing needle by means of a correction plate, so that the front needle tip and the rear needle tip are precisely aligned; fourthly, measuring parameters of a step board are designed, and the design mainly comprises the steps of designing a needle lifting height and detecting the movement speed of the testing needle; fifthly, the flying-probe testing machine is started to detecting open-short circuit functional defects of the printed-circuit board step hole. The detection method for monitoring open-short circuit functional defects of the printed-circuit board step hole has the advantages that the testing needle does not crack up and puncture a testing PAD, the machine is made to achieve automatic and fast mass production, testing efficiency is effectively improved, and the loss of the open-short circuit functional defects of the stepped board is reduced.

Description

technical field [0001] The invention relates to the technical field of open-circuit and short-circuit functional detection of printed circuit boards, in particular to a detection method for detecting open-circuit and short-circuit functional defects of step holes of printed circuit boards. Background technique [0002] Electrical testing is a conventional detection method that uses the test probe to contact the conductive PAD of the printed circuit board to detect whether there is an open circuit in the same line, or whether there is a short circuit or leakage defect between different lines. With the rapid development of electronic information technology, some telecommunications and military customers need rigid-flexible boards and hard boards designed with special processes such as steps to meet actual production needs. This type of product is composed of one or more steps. The outer PAD and the PAD inside the step are on different stepped planes. Conventional testing metho...

AI Technical Summary

Problems solved by technology

Since the lengths of the fixture test pins are equal and there is no space for expansion and contraction, it is impossible to measure the electrical performance of the PAD on different stepped planes; the tip of the test pin of the mobile flying probe machine is a knife with a width of 2-4mil and a length of about 200mil. Type, the flying needle knife cannot extend into the step hole when detecting the step board, and it is easy to damage the test knife or scratch the PCB board when moving left and right, so the printed board manufacturer has fewer steps and the production quantity is not large For large step-type printed boards, the method of manual measurement with a multimeter is generally used to judge the open-short circuit performance of the step position. This method of manually measuring the open-short circuit performance of the step position with a multimeter is not only slow in detection speed and low in efficiency, it is not suitable for mass production. , there is also the risk of artificial omissions and huge claims, which makes printed board manufacturers often look forward and backward when receiving orders, and cannot be imported as regular products

Images